Process control devices, e.g., valve controllers, may be operated in environments that are susceptible to explosions or fires. For example, valve controllers may control valves that control oil flow in a refinery or the flow of chemicals in a chemical plant or manufacturing facility. Valve controllers typically include modules having an enclosure that may accumulate fluids and/or gases from the potentially combustible environments. Sparks or overheating by electronics, wiring, or motors within the modules may ignite a fluid inside the module and initiate a flame, a fire, or an explosion. Because, in many cases, the modules include passages or channels that enable a fluid to flow between the outside of the enclosure or housing and the inside of the enclosure or housing to enable electronics of the module to measure properties of the fluid, there exists the risk that a flame, a fire, or an explosion initiated within the module will spread, via the passages or channels, to the potentially combustible environment outside the module.
To prevent such a flame, fire, or explosion from spreading from the module to the potentially combustible outside environment, a flame arrestor may be disposed within a channel or a passage of the module. A flame arrestor permits fluid to flow through the channel or passage and, at the same time, prevents (e.g., extinguishes) a flame, a fire, or an explosion from reaching the outside environment by absorbing heat associated with the flame, fire, or explosion. In other words, the flame arrestor enables a fluid to enter the module from the outside environment while preventing a fire or explosion from exiting a housing or enclosure of the module and igniting the outside environment.
Pursuant to ASME standards, a flame arrestor needs to be secured, in some manner, within the channel or passage of the module. In other words, a flame arrestor cannot rely on an interface fit (i.e., a press fit) to prevent displacement relative to the channel or passage of the module.